Containers for the vacuum packaging of food products, or in any case items which are perishable if placed in prolonged contact with the atmosphere, have been known for a number of decades. Among these, the most widespread containers in the domestic field for preserving freshly-prepared foods are the rigid containers of generally cylindrical shape, such as jars or pots made of glass, aluminium or plastic, equipped with a sealing lid for closing the mouth. The containers intended for use for vacuum packaging are industrially produced and comprise a lid provided with a valve or similar vacuum sealing device, adapted to reclose an air evacuation hole previously made during the industrial production of such lids. Attachable to such containers is a common pumping device for sucking air and creating reduced pressure (“the vacuum”) therein, e.g. a vacuum packaging machine.
A vacuum sealing device is for example described in the U.S. Pat. No. 2,416,900, and is formed by a valve body housed in a dedicated seat made in a lid arranged for the air-tight and vacuum closure of a jar.
Similar solutions, in which the air evacuation hole is previously made during the industrial production of the container and before the assembly of the valve, are typically used in providing flexible, collapsible containers. Among these, the patent application WO 2005/093303 A1 describes a vacuum sealing device applied to a bag for vacuum packaging foods, which includes a flexible closing body coupled with a valve seat welded by heat-sealing on the border of an evacuation hole made on one face of the bag. The closing body has a sealing diaphragm, adapted to cooperate with a surface of the valve seat surrounding a plurality of radial evacuation openings, in order to ensure the air-tight closure of the container. From the closing body head, there emerges an axial stem whose end, spike-shaped, interferes with a coaxial, annular abutment surface of the sealing device in a manner so as to stably retain the closing body, preventing any translation movement thereof along the stem axis. The diaphragm is flexible and capable of being removed from the surface of the valve seat in an operating suction condition, thus to allow the air evacuation.
A reciprocating mechanical pump, manually actuatable, for sucking air from a receptacle and a multipurpose lid in disc form for closing a mouth of the receptacle and maintaining the reduced pressure created at its interior over time are for example described in the U.S. Pat. No. 5,364,241.
As an alternative to the industrial manufacture of containers equipped with suitable lid for vacuum packaging of the same, artisanal solutions are known for transforming a common air-tight closure jar into a container suitable for vacuum packaging. Such solutions are based on the provision of set of devices, generally comprising a pin or similar tool for punching a jar lid and a plurality of portions of an adhesive film, adapted to be arranged on the surface of the lid at the obtained hole and to allow the air evacuation and subsequent sealing closure of the hole due to the reduced pressure inside the container.
Such solution is at the base of the device known by the commercial name “Pump ‘n’ Seal” of Pioneering Concepts, Inc.